Eddie Dickey, 37, was among those arrested. He said police charged him with “dancing in a restricted area” and held him in jail for about 2.5 hours.

A group of about a dozen people showed up at the memorial to protest a recent court ruling upholding the 2008 arrest of Mary Oberwetter.

Oberwetter was part of a group of 18 people who went to the Jefferson Memorial in April of that year to celebrate the third president’s birthday. Just before midnight, the flash mob began dancing silently to honor “the individualist spirit for which Jefferson is known.” U.S. Park Police warned the group to stop and ultimately arrested Oberwetter, charging her with demonstrating without a permit and interfering with an agency function.

Those charges were later dropped.

But Oberwetter challenged the arrest in court, arguing that it violated her First Amendment right to free expression. In January 2010, U.S. District Judge John D. Bates threw out the lawsuit.

“The purpose of the memorial is to publicize Thomas Jefferson’s legacy, so that critics and supporters alike may contemplate his place in history,” Bates wrote. “The Park Service prohibits all demonstrations in the interior of the memorial, in order to maintain ‘an atmosphere of calm, tranquility, and reverence.’”